Heretofore, in a production process of a semiconductor device, an etching treatment has been performed on a thin film on an Si wafer by making use of an ion or a radical generated in a plasma. As for such plasma etching treatment method, there is, for example, a method in which a thin film on a surface of an Si wafer is etched by a chemical etching mechanism or a physical etching mechanism, or a method in which the thin film is anisotropically etched by electrically accelerating a speed of an ion and, then, drawing it to the surface of the Si wafer. At the time of performing the plasma etching treatment, a member or a container (hereinafter referred to also as “member”) containing quartz glass, aluminum, alumite or the like has ordinarily been used. On this occasion, there is a problem in that a surface of the member itself is also etched and, then, a particle is generated, to thereby contaminate a semiconductor device. For this account, a method in which a tape containing a fluorocarbon resin or an engineering plastic is applied on a surface of the member for the sake of convenience or a method in which a coating film containing the above-described resin is formed has been proposed. However, in the method for applying the tape, since a film thickness of the tape itself is small, etching resistance is not sufficient and also, since a joint portion is formed by applying the tape, a plasma ion is penetrated into a gap formed on this portion and, then, a substrate is partially etched or, since it is difficult to uniformly apply the tape on the surface, a gap is partially generated between the substrate and the tape and, due to the gap, an irregularity is generated on the surface and, then, an irregularity of electric properties is generated on the surface and, due to this irregularity, an insulation failure is partially generated, to thereby cause such a problem as generating a pinhole in the tape. Further, there is a drawback in that a contaminant is released from an adhesive of the tape and, then, properties of the Si wafer are deteriorated.
Further, as for the member which has been coated with the conventional fluorocarbon resin or engineering plastic, since a surface thereof tends to be roughened, the plasma is not well generated and there is also a drawback in that a pinhole is generated in the film or the like.
In order to solve these drawbacks of members containing quartz glass, aluminum, alumina or the like, a member containing ceramics which are excellent in plasma resistance is proposed in JP-A-2001-118910 or the like. However, there is a problem in that a crack or a bent is generated in the member containing the above-described ceramics at the time of calcining and, then, preparation of a large-sized member is not only difficult but also expensive.
Thus, a first object of the present invention is to provide a member for a plasma etching apparatus which has a high plasma resistance, does not perform any abnormal etching to be caused by a partial change of electrical properties and can be used for a long period of time.
Further, a second object of the present invention is to provide a member for a plasma etching apparatus which can handle such a large-sized semiconductor device as being a 12-inch Si wafer.
Still further, a third object of the present invention is to provide a method for producing the above-described member for the plasma etching apparatus.